diff --git a/core/core.pro b/core/core.pro
index 4e0e479..688fad0 100644
--- a/core/core.pro
+++ b/core/core.pro
@@ -16,7 +16,7 @@ SOURCES += \
     context.cpp \
     imetadataplugin.cpp \
     transaction.cpp \
-    emptystringvalidator.cpp
+    emptystringvalidator.cpp \
     data/role.cpp \
     data/permission.cpp
 
@@ -31,15 +31,17 @@ HEADERS += core.h\
     autoform.h \
     transaction.h \
     ivalidator.h \
-    emptystringvalidator.h
+    emptystringvalidator.h \
     data/role.h \
-    data/permission.h
+    data/permission.h \
+    data/core-data.h
 
 unix {
     target.path = /usr/lib
     INSTALLS += target
 }
 
-ODB_FILES = core/data/user.h core/data/role.h core/data/permission.h
+ODB_FILES = core/data/core-data.h
+
 H_DIR = $$PWD/data/*.h
 include(../odb.pri)
diff --git a/core/data/core-data.h b/core/data/core-data.h
new file mode 100644
index 0000000..3d7a05e
--- /dev/null
+++ b/core/data/core-data.h
@@ -0,0 +1,13 @@
+#ifndef COREDATA_H
+#define COREDATA_H
+
+class User;
+class Permission;
+class Role;
+
+#include "user.h"
+#include "role.h"
+#include "permission.h"
+
+#endif // COREDATA_H
+
diff --git a/core/data/permission.h b/core/data/permission.h
index 47e5f5d..a469599 100644
--- a/core/data/permission.h
+++ b/core/data/permission.h
@@ -1,16 +1,15 @@
 #ifndef PERMISSION_H
 #define PERMISSION_H
 
+#include "core-data.h"
+
 #include <QObject>
-#include "role.h"
 #include <QSharedPointer>
 #include <QList>
 #include <QWeakPointer>
 #include <QDateTime>
 #include <odb/core.hxx>
 
-class Role;
-
 #pragma db object
 class Permission : public QObject
 {
diff --git a/core/data/role.h b/core/data/role.h
index 9eeda92..43d2074 100644
--- a/core/data/role.h
+++ b/core/data/role.h
@@ -1,18 +1,15 @@
 #ifndef ROLE_H
 #define ROLE_H
 
+#include "core-data.h"
+
 #include <QObject>
-#include "user.h"
-#include "permission.h"
 #include <QSharedPointer>
 #include <QList>
 #include <QWeakPointer>
 #include <QDateTime>
 #include <odb/core.hxx>
 
-class Permission;
-class User;
-
 #pragma db object
 class Role : public QObject
 {
diff --git a/core/data/user.h b/core/data/user.h
index bace0b2..57c0e35 100644
--- a/core/data/user.h
+++ b/core/data/user.h
@@ -1,17 +1,15 @@
 #ifndef USER_H
 #define USER_H
 
+#include "core-data.h"
+
 #include <QObject>
 #include <QString>
-#include "role.h"
 #include <QSharedPointer>
 #include <QList>
 #include <QDateTime>
-
 #include <odb/core.hxx>
 
-class Role;
-
 #pragma db object
 class User : public QObject
 {
diff --git a/core/emptystringvalidator.h b/core/emptystringvalidator.h
index c060f86..ac796b3 100644
--- a/core/emptystringvalidator.h
+++ b/core/emptystringvalidator.h
@@ -4,7 +4,9 @@
 #include <QString>
 #include "ivalidator.h"
 
-class EmptyStringValidator : public IValidator
+#include "core_global.h"
+
+class CORESHARED_EXPORT EmptyStringValidator : public IValidator
 {
 public:
     EmptyStringValidator(QWidget *widget, const QString &errMessage);
diff --git a/core/ivalidator.h b/core/ivalidator.h
index d096a7d..f0aa0e5 100644
--- a/core/ivalidator.h
+++ b/core/ivalidator.h
@@ -4,7 +4,9 @@
 #include <QWidget>
 #include <QString>
 
-class IValidator
+#include "core_global.h"
+
+class CORESHARED_EXPORT IValidator
 {
 public:
     IValidator(QWidget *widget, const QString &errMessage)
diff --git a/core/transaction.h b/core/transaction.h
index 2fd84c0..29eb3d6 100644
--- a/core/transaction.h
+++ b/core/transaction.h
@@ -4,7 +4,9 @@
 #include <odb/database.hxx>
 #include <odb/transaction.hxx>
 
-class Transaction
+#include "core_global.h"
+
+class CORESHARED_EXPORT Transaction
 {
 public:
     Transaction();